Dental x-ray images are taken routinely as part of a normal dental exam to provide the dentist with information relating to the internal structure of a patient's teeth, jaw bones, and surrounding soft tissues. Dental x-rays can reveal cavities and other hidden dental problems, such as impacted teeth, that are not easily diagnosed by a simple visual examination of the patient's mouth. Dental x-rays may also be obtained during follow-up exams to determine the effectiveness of previous dental treatments and otherwise determine the health of the patient's teeth.
One type of dental x-ray machine is a panoramic imager. A panoramic imager typically includes an x-ray source and an imaging device that are maintained in an opposing relationship by a rotating arm. The x-ray source and imaging device are spaced sufficiently apart horizontally by the rotating arm to allow a patient's head to be positioned between the x-ray source and imaging device. When the x-ray source is activated, electromagnetic radiation penetrates the patient's head and excites the imaging device, thereby producing an image that corresponds to the density of the bone and tissue matter in the path between the x-ray source and the imaging device. To generate a panoramic image, the arm is rotated about the patient's head while the imaging device captures multiple x-ray images from different angles. These images are then processed to produce a single panoramic image of the patient's teeth and jaw.
In order to minimize distortion and blurring of the panoramic image, the movement of the rotating arm is designed to: (1) maintain a constant distance between the patient's teeth, the imaging device, and x-ray source while the arm is rotated, and (2) maintain the axis connecting the x-ray source and imaging device in an orthogonal orientation with respect to the patient's dental arch. However, because anatomy varies from patient to patient, the movement of the rotating arm is generally a compromise that provides acceptable results over a normal range of patient sizes and shapes. Because of the sensitivity of image quality to the distances and angles between the patient's head and the x-ray imaging components, obtaining clear images requires that the patient be properly positioned within the machine. A patient that is not properly positioned will result in inconsistent distances and angles between the patient's teeth, the x-ray source, and the imaging device as the arm is rotated. As a result, a patient that is even slightly out of position will typically produce images that are blurry and distorted. A dental panoramic imager operator may not be aware of the specific problem causing the poor image quality, resulting in the operator taking multiple images before obtaining a satisfactory result. Thus, an out of position patient may result in wasted time and effort, as well as additional unneeded exposure to x-ray radiation.
Therefore, there is a need for methods and systems of providing feedback to panoramic imager operators and other medial imaging system operators to improve the imaging process.